I do notice that even the nicer side of middle-class houses use worse finishing materials now. I've got relatives in ones built in the 80s and early 90s (and I lived in such myself, for many years). Solid wood doors, actual wood trim, throughout. Even cheap houses then at least had hollow wood veneer doors and real wood trim. Now? Hollow particle board (so, basically heavy cardboard) doors, particle board trim, even on a half-million dollar house (in a market where that's still pretty damn expensive).